2011-04-25 폴리우레탄계 접착제

1 2011/04/25 - , 1 - - i@ 1937 Otto Bayer (1902 - 1982) develops the novel polyisocyanate-polyadditionprocess. The basic idea py ypypwhich he documents from March 26 1937 relates to spinnable products made of hexane-1,6-diisocyanate (HDI) and hexa-1,6-diamine (HDA). Publication of German Patent DRP 728981 on November 13 1937: "A process for the production of polyurethanes andpolyureas"The team of inventorspolyurethanes and polyureas. The team of inventors consisted of: Otto Bayer, MbPlFabricsMembraneFoamsPanels Sports AutomobileShoesStadium AutomobilePaints adhesiveTapesLeather3 Leather Human organic4 Versatile classes of polyurethane has been developed for sixty yearsyearsRich choice of building blocksBasic reaction between diisocyanate and polyolsPolyether polyolpolyolAromaticdiisocyanateDiamine chainextender5 Segmented StructureSoft segment: MatrixSoft segment: MatrixOHOOHn Hard segmentOOHOHNHHard segment: Physical cross-linkingOCNNCOOHOHOHONH2NH26 vs.

2 NRSSSSSSSS heatSNRC rosslinkingstressrelaxationSulfur: S8in natureSSSnpolysulfurNetwork polymer Elastomer = low Tg + crosslinking (low)pygg() TPE , , 7 (solvent-based)PolyolChain extenderChain extenderDiisocyanateDiisocyanateUrethane & Urea Reaction8 1 : NCO-terminated prepolymer in solvent ( ) 2 :OHorNHterminatedprepolymerin solvent + 2 : OH or NH2-terminated prepolymerin solvent + Crosslinker (polyisocyanate) ( , , 2-24 ) Block :Blockedprepolymer+Crosslinker(polyisocy anate)( Block : Blocked prepolymer+ Crosslinker(polyisocyanate) ( , , 60-100 , 1 ~ 1 ) (TDI, MDI)*IPDI , HDI (TDI, MDI) IPDI , HDI 80 , : MEK, Acetone, Ethyl acetate 9 NCO-terminated prepolymer NCO/OH : 2~3 Polyol : 2 2 Polyol.)

3 1000~4000 g/mol10 (2,3 ) 11 R-NCO + H2OR-NH2+ CO2H2OR-NH2+ NCO-R+OCNRNCONHNHOCNRNNHRNCOOH11(Urea)(B iuret)H2O+OCNRNCONRNROHONHROCN12 Biuret Allophanate p 13 ( ) NCO/OH ~ - 3 Hydrophilic functionalityDMPA, DMBA (COOH)Sulfonate, Sulfate, iNeutralization AgentPhase inversion or Pl iPrepolymer pouring14 1 Blocked polyisocyanate dispersion by hydrophilic py ypyypmodification Isocyanurate trimer of HMDI and HDIHMDI: CH3 -R-N=C=OBlocking: oxime phenol etcBlocking: oxime, phenol, Emulsion +Base Emulsion + Hydrophilic polyol or hydrophobic polyol/ionic extender Aqueous solution of crosslinker : NCO/OH ratio ~.

4 NCO/OH ratio ~ ( ) 15 hard segment ( ) T Tg hard segment , , 16 - 17 18 ? (substrate) ( ) ( ) ( ) , ( , , ) : , , (thinner) ( ) : /.

5 19 ( , , , ) , , , , / Coupling agent Coupling agent , 20 1 (initial adhesion tackiness) 1 (initial adhesion, tackiness) 1 : , , (static adhesion) 24-48 : , , , / , 2 , , , , , , , !21 (adhesion) (i t f i l f ) : (interfacial force) (interfacial force) (interfacial force): (chemical bond) covalent, ionic (h i lb d)dWlHbd.

6 (physical bond) van derWaals, H-bond, interlocking (rough surface), electrostatic, adsorption, Mechanical It l kiInterlockingSEM image and optical micrograph of abraded steel surface and crosssection of epoxy/steel 22 Interface, respectivelyPeel adhesion of electroformed copper foil to epoxy laminates23 True adhesion strengthTh d itit Thermodynamic quantity Regardless of test rate Intrinsic adhesion strengthhdikfdhi Thermodynamic work of adhesion, WaWa= S+ L energy(tension)Ex) For non-polar substrate, S, L~ 25mJ/m2, thus Wa~ 50mJ/m2reduction byS-L interaction24 Practical adhesion strengthTh d i & ki ii Thermodynamic & kinetic quantity Depends on test rate and temperature due to viscoelasticenergy dissipation.

7 Dh i Ga: Adhesion energy ( )G(~1-10J/m2)=G0+GdEnergy dissipationGa(110J/m) G0+ GdIntrinsicgy pby deformationIntrinsic adhesionGd= f(crack growth rate, temp. strain)25 ? (wettability) ? (y) L Lv s SL s SL SV SV= SL+ LVcos 25 F( ) = Lcos 26 ? (Importance of wettability)Fully wettedNon-wettedPE adhesiveEpoxy adhesivePE adhesive SV= SL+ LV ( )( )Epoxy substratePE substrate SV= SL+ LV ( )( )*(0~-1)( ) . NylonMetal (surface treatment) SV Te f l o n27 Adhesion Cohesion Adhesion: ( ) Cohesion: ( )PeelforceCrackCrackCrackStick-slipCrack CohesiveftInterfacialfracture& GlassyfracturePeel ratefracture28 Peeling of uncrosslinked rubber adhesiveCohesiveCohesive rupture of adhesivePeelforcefailureInterfacialfailu reInterfacial pointsact as crosslink pointsact as crosslink pointslPeel rate29 Adhesive thickness and fracture29 PMMA adhesive with metal substrate (smooth surface)30 : 3031 : (PMMA): PF PU UPESPF.

8 Phenol-formaldehydePU l th (PMMA): PF, PU, UPES : NC, PU, CNA PP: SCPU: polyurethaneUPES: unsat. PE-co-PSNC: nitrocelluloseCNA: cyanoacrylate PE: SC, PB PTFE: PAE, PF :NRPPEPPUC:cya oac y ateSC: silicone PB: polybutadiene PAE: polyamide epoxyNRPit ilbtdihli : NRP, PEP, PU PC: UPES, PU, PSE Nylon: RF, NRP NRP: nitrilebutadiene phenolicPEP: phenolic epoxyPSE: polysulfide epoxyRF: resorcinol formaldehyde y32 : Coupling agent Silane Coupling AgentSilane Coupling AgentR = -C=C, -OH, -Cl, -NH2, -NCO, -COOH, : Coupling agent34 : (joint design) , , 35 Tensile strength (a) kgf/cm2 Shear strength (b) kgf/cm2 Shear strength (b) kgf/cm Cleavage strength (c) kgf/cm2 Peeling strength (d) kgf/cm3536 Peel strengthTensile strengthShear strengthCleavage strengthCleavage strength3637 Cohesive failure (A)Adhesion failure (B) Adhesion failure (B) Mixed failure (C) Substrate failure (D)3738 Adhesion Testing method , adhesion.

9 , , , , Adhesion : resolution level Testing Method: Testing method : .Undetected residual stresses39 40 (Diisocyanate)OCNRNCO (blocked isocyanate)4041 42 NCO2 NCOOCNTDINCONCO>>11timesMDITDI(para NCO)H2 CNCO2 NCONCOTDI(ortho NCO)>>H2C6 HDINCON eopentylicNCO of IPDINCOS econdaryNCO of IPDI>20timesNCO of IPDINCO of IPDI43 44 45 (Polyol) 90%.

10 (PPG), (PTMG) : , : , : : , , , 4546 (Polyether polyols) (ypy) : PPG, PTMG and PEG UV 47 (Polyester polyols) :adipateandcaprolactone : adipateand caprolactone 48 NCO , 2-6 , 1 ,NCO- 3 (TEA) 49 Characteristics of WPUDS trong hydrogen bonding of urethane and urea groupsStrong hydrogen bonding of urethane and urea groupsGood flexibility, long durability, and good chemical-resistanceV tilit i t i l l ti d difi tiVersatility in material selection and modificationTfWPUDTfWPUDType of WPUDType of WPUDN eutralization EmulsificationNeutralization Emulsification-- Ionomer (cationic, anionic) and nonionic typesIonomer (cationic, anionic) and nonionic types()yp()ypExternal EmulsificationExternal Emulsification--Polymer and Polymer and prepolymerprepolymer emulsion, blocked (poly)emulsion, blocked (poly)